The supersonic near-wake flow experiment conducted by Dutton on a cylinder with 10 degrees angle of attack was studied numerically with Delayed Detached Eddy Simulation (DDES) method. The wind tunnel test section were included in the geometry model to examine if its omission led to the unsuccessful prediction of several important flow features in previous studies. Flow structures were compared to experiment measurements, Gaitonde's k-ε model results and our previous Monotonically Integrated Large Eddy Simulation (MILES) results. It was revealed that with present geometry model and numerical method, good agreements with wind tunnel experiment result were obtained, including the wave structures, density fields and velocity fields. In particular, the inclusion of wind tunnel test section wall in geometry model reproduces the finite area nozzle exit flow and the expansion wave behind the recirculation zone in the actual experiment setup, which lead to correct prediction of the position of maximum streamwise velocity point. The present simulation also reproduced the uniform pressure profile and value observed in the experiment and the deviation between computation and experiment was within 10%. The flow field data obtained was further analyzed to investigate the vortex surface shape and recirculation region shape in near wake flow with non-zero angle of attack and significant differences were found compared to the zero angle of attack case. The vortex surfaces show a non-axisymmetric slitting movement in the near wake region, which gives an explanation to the non-circular density contour pattern on streamwise flow field slices. The recirculation region shape was identified with zero isosurface of streamwise velocity and was found to be of complex three-dimensional shape with maximum length beside the symmetry plane and a local minimum at windward side of the symmetry plane, which is significantly different from that of zero angle of attack case. The observation that the length of the recirculation zone was greatly reduced on the symmetry plane at non-zero angle of attack in previous study is due to the aforementioned local minimum on the symmetry plane. The reduction of recirculation length is much less if we consider the three-dimensional shape of the region.

采用延迟分离涡模拟(DDES)方法对Dutton在10°攻角圆柱体上进行的超音速近尾流流动实验进行了数值研究。风洞测试部分包含在几何模型中，以检查其遗漏是否导致先前研究中几个重要流动特征的预测不成功。将流动结构与实验测量值、Gaitonde 的k - ε 进行比较模型结果和我们之前的单调集成大涡模拟 (MILES) 结果。结果表明，采用现有的几何模型和数值方法，与风洞实验结果吻合良好，包括波浪结构、密度场和速度场。特别是几何模型中风洞试验段壁的加入，再现了实际实验设置中的有限面积喷嘴出口流和回流区后面的膨胀波，从而正确预测了最大流向速度点的位置。本模拟还再现了实验中观察到的均匀压力分布和值，计算与实验之间的偏差在 10% 以内。进一步分析获得的流场数据以研究具有非零攻角的近尾流中的涡面形状和再循环区域形状，并且与零攻角情况相比发现显着差异。涡旋面在近尾流区域呈现非轴对称的纵切运动，这解释了流向流场切片上的非圆形密度等高线模式。再循环区形状被识别为流向速度的零等值面，并发现其为复杂的三维形状，在对称面旁的长度最大，在对称面的迎风侧有一个局部最小值，与零等值面有显着差异。攻角情况。在先前的研究中观察到在非零攻角的对称平面上回流区的长度大大减少是由于上述对称平面上的局部最小值。如果我们考虑该区域的三维形状，则再循环长度的减少要少得多。